JIT  is a management  philosophy  that  eliminates of manufacturing  waste  by production  the  right part in the right place at the right time. Waste results from any activity that adds cost without  adding value  should improve profits by reducing inventory levels ( increasing the inventory turnover rate)  improving product quality   reducing production and delivery lead times. And  reducing  other  costs ( such  as those associated with machine setup and equipment breakdown) . JIT concept applies  to repetitive  manufacturing processes in which  the same products and components are production  repetitively. The  general idea is to establish flow processes by linking work centres so that  there is an  even balance  flow of materials thought  the entire production process.

There are seven  kinds  of wastes according to shigeo,  shingo a recognized JIT authority and an  engineer at Toyota motor company.